JoeFrank

I have a 1988 80 front wheel drive manual tranny with about 160K on the clock. Recently, within the past 2 weeks, it has had trouble starting when the engine is cold. After I have been driving for a while and the engine is hot a restart is no problem at all. After it has been started there are also no problems. If anyone has any suggestions I would appreciate it. I think that it is the cold start valve or sensor or whatever, I'm not sure. I would like to do the repair myself so as much help as possible is always appreciated.

Also, it makes an odd rattling noise when I'm in gear, but not when I rev the engine out of gear. Any insight on this would also be helpful.

Thank you!!
~Joe

Nkugs90

your fuel injectors and sleeves. I had a similar problem to that on my 80. It could also be the fuel pump check valve. I happen to have a set of barely used fuel injectors and an unused check valve left from my parts 80. The injectors have about 3000 miles on them. As for the the tranny noise that sounds like it could be something internally on your tranny, or possibly a throw out bearing. I also have one of those, ha ha sorry to make this all sound like a sales picth.

YucatanAudi

Those are replaced when you replace the clutch plate. If that hasn't been done, you may be about due.

On the starting problem, it really is pretty difficult to guess.

When is the last time you changed the plugs? The distributor cap & rotor? The plug wires? The fuel filter? The Air Filter? etc. In other words, what is the status of ALL the routine maintenance? Then, after going through that, it would be easier to determine why a cold start problem exists.

One thing about older Audis that sometimes helps: Just turn the key on so you hear the fuel pump whine and wait 3-4 seconds, then turn the key to start. Often does the trick. That lets fuel pressure build through the system before you start cranking it.

I agree that it could be the injectors and sleeves, but it could be a lot of routine mtce things cheaper/easier than those. Do the routine first, just cuz you should anyway.

JoeFrank

Yeah. I really stay on top of all the routine matenance and the car starts perfectly after the engine is warm. I really don't know where to start. I have also cleaned the injectors in the past 8-12 months as well. It is also the original clutch on the car and I will be replacing that soon. As far as the cold start, I am still without a clue. I really appreciate the help and will look over the things that you mentioned.

Thanks again,
Joe

YucatanAudi

On the 5 cyl, there is one (the "6th" injector) which enriches the fuel for a bit according to the temp sender's input into the ECU (computer). I think the max time is about 10 seconds and tapers down if the engine is 'warm' or has been run recently.

Also, I'd check everything for vacuum leaks and the ISV - has it been cleaned lately?

The link has some info on the 5cyl cold start injector.

Also, check Huw Powell's site for running problems. He has a great "Poor Running" checklist: [url]On the 5 cyl, there is one (the "6th" injector) which enriches the fuel for a bit according to the temp sender's input into the ECU (computer). I think the max time is about 10 seconds and tapers down if the engine is 'warm' or has been run recently.

Also, I'd check everything for vacuum leaks and the ISV - has it been cleaned lately?

The link has some info on the 5cyl cold start injector.

Also, check Huw Powell's site for running problems. He has a great "Poor Running" checklist: http://www.humanspeakers.com/audi

Also a couple more links:
https://forums.audiworld.com/9080/msgs/13841.phtml

https://forums.audiworld.com/9080/msgs/13721.phtml<ul><li><a href="https://forums.audiworld.com/9080/msgs/323449.phtml">https://forums.audiworld.com/9080/msgs/323449.phtml</a></li></ul>

JoeFrank

Yeah the 4cyl has a cold start valve. I ordered a new one to see if that is the problem. The part is comming in tomorrow, so I'll probably install it tomorrow as well. Do you know if I will leak any fuel when I install it?

Thanks again,
Joe

YucatanAudi

You can avoid this by running the engine and pulling out the fuel pump relay so it runs out of gas. (That will make it real easy to get started again! Not)

Or just have some rags ready to soak up the gas.

If you find you are without pressue when you disconnect a line, your problem may be a fuel pump check valve which should hold your pressure while shut off. This valve is located on the fuel pump itself on a 5 cyl. Probably the same on a 4, but not sure.

JoeFrank

I replaced the cold start valve and the problem persists. Should I try replacing the Coolant temperature sensor? Is it necessary to replace even if the engine temp is displayed on the cluster correctly?

Thanks
Joe

YucatanAudi

where to head next, that may tell you.

Temp Senders: On the 5cyl engine, there are separate sensors for the ECU (computer) and the guages. Dunno about the 4 cyl. Do you have a factory manual?

Sandy Wishart

Put spare key in to move my convertible started then stopped used my main key does the same thing now with that flashing key on dash any ideas please on what's happened before I used spare key all was fine